Coffee Cup Lens Hood.

Lens hoods are used to prevent light from hitting the lens from the side which reduces the contrast of your picture and creates flare.
Pictures taken with a lens hood will generally have richer colors and deeper saturation.
Furthermore, they often protect the camera when dropped or bumped.

Lens hoods are usually expensive (for dSLR cameras) and as far as I know, non-existing for compact cameras.

This I'ble will show you how to make one out of a coffee cup and it's my entry for the "Coffee Cup Challenge". If you like it, don't forget to vote for me.

Sounds great, but there are limitations. You should not use a lens hood when using a flash and when photographing with a wide lens angle ("zooming out") as part of the hood may become visible. In this case you can shorten the hood or cut it into a flower shape (as with dSLR hoods).

* a coffee cup.
* a paper clip.
* a rubber band.

 
Cut out the bottom and perforate the cup on both sides.
Stick the elastic band through.

 
Close the loop with the paper clip.